As explained in application Ser. No. 07/472,400, blends of polyethylene terephthalate (PET) and nylon (e.g., MXD6 nylon) with and without cobalt provide oxygen barrier properties superior to most known barrier materials (almost zero permeation).
These blends, however, can be improved, particularly in the areas of optical properties and moisture sensitivity. Blends of PET/MXD6 nylon can have a greenish color and can rapidly lose their superior oxygen barrier properties when the relative humidity (RH) is above 90%. As will be shown hereinafter, these properties are improved by the present invention.
Application Ser. No. 07/472,400 also relates to U.S. Pat. No. 5,281,360 PET/MXD6/PET multilayer structures. As will be shown hereinafter, these structures can exhibit improved barrier properties by the present invention involving the addition of a cobalt compound, such as cobalt octoate to these structures. In particular, by the present invention films of MXD6 with cobalt octoate are a significant improvement in terms of barrier properties over MXD6 films without cobalt.
In addition, reference is also made to U.K. Patent Application GB 2230 530 A, published Oct. 24, 1990 (claiming priority from U.S. Ser. No. 375,957, filed Jul. 6, 1989 abandoned and GB 8901 760, filed Jan. 27, 1989) which relates to an oxidizable polymer which is the condensation polymer product of: (I) H.sub.2 N--R.sub.1 --R.sub.2 --R.sub.3 --NH.sub.2 (wherein each of R.sub.1 and R.sub.3 represents a non-aromatic group containing a saturated carbon atom adjacent to the respective --NH2 group, and, may be the same or different, and, wherein R.sub.2 represents a substituted or unsubstituted arylene group) and (II) HO.sub.2 C--RE.sub.4 --R.sub.5 --R.sub.6 --CO.sub.2 H (wherein each of R.sub.4 and R.sub.6 represent a direct bond or a non-aromatic group containing at least one carbon atom, and, may be the same or different, and wherein R.sub.5 represents a substituted or unsubsituted arylene group), wherein the molar ratio of (I) to (II) is 1: X.sub. II where X.sub.II is greater than or equal to 0.05; and, the catalyst for the oxidation of the oxidizable polymer is copper acetate or cobalt acetate.
UK Patent Application GB 2230 530 A fails to disclose or suggest: multilayer structures including a layer of a blend of nylon and a cobalt compound, e.g., A/blend (e.g. MXD6 nylon and cobalt octoate)/B wherein A and B are from any suitable materials, e.g., PET, PBT or polycarbonate, or the like, and A and B can be the same material or different materials; blends of nylon and a cobalt compound, such as blends of MXD6 and Cobalt octoate; blends of PET, nylon such as MXD6, and a cobalt compound such as cobalt octoate; blends of polybutylene terephthalate (PBT), nylon such as MXD6, and a cobalt compound such as cobalt octoate; blends of PET and/or PBT and nylon (e.g., MXD6); multilayer structures of X/PET and/or PBT and nylon (e.g., MXD6) and cobalt compound (e.g., cobalt octoate)/Y wherein layers X and Y can be the same or different and have moisture resistant properties and preferably comprise PET, PBT or polycarbonate, or the like; or, blends of germanium and antimony catalyst based PET and/or PBT (as opposed to antimony, cobalt, and manganese catalyst based PET), nylon (e.g., MXD6) and a cobalt compound (e.g., cobalt octoate) which exhibit neutralized green or yellow color and/or shortened incubation (aging) period. Accordingly, GB 2230 530 A fails to teach or suggest the present invention.